Piracy of motion picture films constitutes a major loss of revenue for the motion picture industry. The advent of low cost recording technology, in the form of VHS and DV videotape recorders, and Digital Versatile Disk (DVD) recorders has dramatically reduced the investment required to illegally record movies. Moreover, the relative small size of such devices facilitates their transport into a screening facility to make unauthorized copies of copyrighted content.
Most screening facility operators make efforts to stop those who would copy motion picture films if for no reason than to avoid allegations by the content providers of complicity with such illegal activity. However, not all screening operators exercise vigilance, and through indifference, some operators allow pirates to make illegal copies of motion picture films. In rare instances, operators of a screening facility have actively cooperated in such illegal copying. Tracking the perpetrators of such illegal activity has proven difficult since movie studios typically supply hundreds if not thousands of release prints of a major motion picture to movie theaters across the world. Since each release print appears identical to every other, knowing which print served as the master of an illegal copy has traditionally proven quite difficult.
Providing a unique watermark on each release print would greatly facilitate the tracking of illegal copies. However, the nature of the watermark must not appear so prominent on the release print as to alert a potential pirate of its existence. Conversely, detection of the watermark should not prove so onerous as to make adoption impractical. Lastly, the presence of the watermark should not alter viewing of release print by theater patrons.